Variable voltage control



May1s,194s.' l 'E HHAUG 2,441,814

VARIABLE vonuqz coN'rn-OL Fnea Feb., a., 1944 la f IN VEN TOR.

Patented May 18, 194g VARIABLE VOLTAGE coN'rnoL Y Eugene H. Haug, Glencoe, lll., asslgnor, by direct and mesne assignments, to Modern Controls Inc., Chicago, Ill., a corporation of Delaware Application February 8, 1944, Serial No. 521,509

1 claim. 1

My invention relates to a voltage control device and more particularly to a control device which does not require taps for obtaining various voltages, and furthermore a, voltage control device by which the voltage can be varied at a uniform rate and without steps.

An object of my invention is to provide' a voltage control device which is either manually or automatically operated to obtain any desired voltage at a uniform rate without increasing the exciting current in the primary supply circuit.

A further object of my invention is to provide any change in voltage, which is of constant potential characteristic, when taken from a constant potential source.

In the electrical art it is desirable to obtain any value of constant potential without tap change for electric furnaces, light variation, motor controls, electro-chemical applications, rectiiication, electric signaling, pipe thawing and rail heating devices, blowers, fans, and pumps, and for other uses. 4

These, and other objects that will be made apparent throughout thek further description of my invention, are obtained by voltage control apparatus hereinafter described and illustrated in the accompanying drawings, wherein:

Figure N o. 1 is a general wiring diagram showing control of the output voltage by varying the air gap of any part of the core of the transformer on which the secondary winding is incorporated.

Figure No. 2 is a general Wiring diagram showing control of the output voltage by varying the air gap of any part of the core of the transformer which does not incorporate the secondary winding.

Referring to Figure No. 1, the alternating current supply is connected to wires I5 and I5, which in turn are connected to primary coil I4 of transformer i3. A tertiary winding I2, which is mounted on transformer core is connected to capacitor Il by means of wires 9 and I0. Secondary coil l of transformer `Il is mounted on movable transformer core 8. The load is connected to secondary coil 'I by means of wires l and i. An operating wheel I is fastened to threaded shaft 2 and is operated at support I. Shaft 2 is furthermore connected by a swivel incorporated in support 4, which is fastened to core 5.

The operation of Figure No. 1 is as follows: i

when hand wheel I is turned to the left core I age in wires 5 and 6. At the same time the ux interleakage of tertiary winding i2 increases proportionally, increasing the voltage to capacitor i I and thereby producing a leading counter ilux. Sin-ce the counter flux in secondary coil I has been reduced by the same proportion that counter ilux in teritary winding I2 has been increased, the total counter flux to primary coil i4 will remain the same, thereby holding the exciting current to primary coil I4 constant under all conditions of voltage variations The operation of Figure No. 2 is the same as in Figure No. 1, the only difference being Athat in Figure No. 1 thel movable core incorporates one of the windings while in Figure No. Z it does not.

While I have described what I at present consider the preferred embodiment -oi my invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from my invention, and I therefore aim in the appended claim to cover all such changes and modincations as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

In combination with a constant potential transformer, a primary winding, a tertiary wind- A voltage in the output circuit of said secondary increases its air gap from transformer I3. This Y in turn causes the flux interleakage in secondary coil 1 to be reduced, and thereby reduce the voltcoil while at the same time maintaining a constant ilux interleakage in said primary coil, and thereby holding the primary exciting current constant under all secondary voltage conditions.

EUGENE H. HAUG.

REFERENCES crran l The following references are of record in the file of this patent:

UNITED ASTATES PATENTS Number Name A Date 1,385,170 Herz July 19, 1921 1,559,570 Lucas Sept. 14, 1926 1,756,875 Montsinger Apr. 29, 1930 2,001,557 Ohlsen May 14, 1935 2,207,234 Bohm July 9, 1940 2.340.791 Burdick Feb. 1, 1944 

